Research On Pre-Splitting Blasting Design Expert System And Its Application In Cutting Excavation Of Expressway

Landform of China's western region is complex and mountain is high and steep. The expressway must pass through lots of massif while being constructed, and quantity of cutting excavation is great. Taking optimum pre-splitting blasting technology in the different geological conditions is a key problem in construction of expressway in mountainous area. The paper researches the relations between blasting effect and blasting parameters, including diameter of drill, non-coincidence coefficient, hole spacing, hole row-spacing, cartridge diameter, charge per hole, density of line charge, charging structure and detonating manner, and how to adjust the blasting parameters to get the best blasting effect under the given geological condition. According to the principle of expert system and neural network, Visual C++ 6.0 and SQL Sever 2000 are used to develop a pre-splitting blasting design expert system for cutting excavation of expressway. The key algorithm of the expert system is the BP neural network. The expert system's engineering database has the data of the correlative physical-mechanical property of rock, parameters of industrial explosive, blasting accessories and drilling machine. The system can give the blasting scheme intelligently and experientially, predict the blasting effect.The pre-splitting blasting design expert system can be applied to cutting excavation of the other expressway. First of all, engineering database of the system should be adjusted according the fact. And do some pre-splitting blasting experiment in site, accumulating blasting engineer instances on the base of the in site experiment. Then the neural network must be trained by the pre-splitting blasting engineer instances of the engineering database, and the system gives some typical design examples according to the typical geological conditions, to test the system's validity. When the system runs steadily, it can supervise the practice of pre-splitting blasting in cutting excavation, and enhance the reliability of in site pre-splitting blasting design scheme, efficiency and quality of construction. So the stability of excavated slope is enhanced.